Signal detection method based on double Kalman closed-loop feedback control

The invention discloses a signal detection method based on double Kalman closed-loop feedback control, and belongs to the field of optical fiber hydrophone detection. After the original underwater acoustic signal and the two paths of frequency-mixed reference signals are subjected to product, filtering, division and arc tangent, the phase difference is detected by an analog-to-digital converter; the phase difference signal is received through first Kalman filtering, noise in original water sound and noise observed by an analog-to-digital converter are considered, a phase difference estimated value at the current moment is output, and the total feedback phase at the current moment is calculated; the second Kalman filter receives the total feedback phase at the current moment, takes execution noise and analog-to-digital converter observation noise into consideration, outputs a phase pre-estimated value at the current moment, and feeds back the phase pre-estimated value to two paths of reference signals for freq